The present invention relates to composite molded articles composed of a wood veneer and a synthetic resin molded product and a method for manufacturing the same.
Synthetic resin molded products having grain pattern have been used widely in interiors of cars, furniture, electric devices.
The following have been hitherto been provided as the composite molded articles having a grain pattern
(1) Those produced by an insertion molding method in which a surface material backed with sliced veneer, wood veneer, plywood, unwoven fabric or the like is placed in a metal mold for injection molding and a synthetic resin is injected onto the backside thereof.
(2) Those produced by subjecting a synthetic resin molded product to surface treating as by sanding, chlorination or the like to increase adhesiveness, coating an adhesive, and pressing thereon the above-described surface material.
The composite molded articles described in (1) and (2) above have a good designability. However, the composite molded articles tend to give rise to rejected products which have caused cracks in the wood veneer or the like that is present on its surface when they have complicated shapes. In order to avoid this, attempts have been made to prefabricating surface materials as by vacuum molding prior to use. However, this countermeasure has been ineffective because the wood veneer or the like causes cracks in the step of the prefabricating.
In particular, those produced by using an adhesive as described in (2) above tend to suffer from the occurrence of protrusion of the adhesive, stain, slipping out upon the bonding or the like. Also, they have a defect that it takes a long time to set the adhesive upon the production.
Furthermore, when surface finishing is conducted by buffing after coating the surface of the composite molded articles, the synthetic resin provided on the backside softens at the interface between it and the surface material due to frictional heat upon the buffing, thus forming minute depressions and protrusions on the surface of the molded surface. Therefore, buffing cannot be adopted for the surface finishing of the composite molded articles described in (a) and (2) above, and mirror surface finishing by spraying up or matt finishing has had to be adopted.